Hi, what type of soil are you using, and the nutrients what line is it.
I am using bio bizz all mix soil and on my present grow I am on day 33 and only today I started feeding my plants.
There is enough nutrients in the soil already, if I started feed on seedlings they would die off.
It is all about the right timing, so don't worry it is all experience and is all good.
You will get there eventually, it took me about 4 years to understand to some level the live cycle of our beloved plants.
Try not to feed them strait away, give them just water and perhaps some root stimulant like Rizotonic then sit back and watch what happens .
Do it differently from the last run, that my 5 cents ( just giving you my example, don't have to follow it)